3D printer

--[[
        3D Print
        A printing program for use with NPaintPro

        By NitrogenFingers
]]--

local activeCommander = -1
local operatingPrint = false

--Whether or not the print can be ended
local function endPrint()
    operatingPrint = false
end

--The list of all commands the printer can be ginve
local commandList = {
    ["FW"] = { turtle.dig, turtle.forward };
    ["BK"] = turtle.back;
    ["UP"] = { turtle.digUp, turtle.up };
    ["DW"] = { turtle.digDown, turtle.down };
    ["TL"] = turtle.turnLeft;
    ["TR"] = turtle.turnRight;
    ["TU"] = { turtle.turnLeft, turtle.turnLeft };
    ["PF"] = { turtle.dig, turtle.place };
    ["PU"] = { turtle.digUp, turtle.placeUp };
    ["PD"] = { turtle.digDown, turtle.placeDown };
    ["SS"] = turtle.select;
    ["RF"] = turtle.refuel;
    ["DE"] = endPrint;
}

--Splits a string according to a pattern into a table
local function split(str, pattern)
  local t = { }
  local fpat = "(.-)" .. pattern
  local last_end = 1
  local s, e, cap = str:find(fpat, 1)
  while s do
    if s ~= 1 or cap ~= "" then
      table.insert(t,cap)
    end
    last_end = e+1
    s, e, cap = str:find(fpat, last_end)
  end
  if last_end <= #str then
    cap = str:sub(last_end)
    table.insert(t, cap)
  end
  return t
end

--Listens for any instructions given referring to identification and activation. Once activated, the mode exits.
local function respondToQuery()
    while true do
        print("Listening for ACT/ID query")
        local id,key = rednet.receive()
        print("Received : "..key)

        if key == "$3DPRINT IDENTIFY" then
            print("Requested Identification")
            rednet.send(id, "$3DPRINT IDACK "..os.getComputerLabel())

        elseif key == "$3DPRINT ACTIVATE" then
            print("Requested Activation")
            activeCommander = id
            rednet.send(id, "$3DPRINT ACTACK")
            break
        end
    end
end

--Performs the print. Follows instrutions as given, and responds as necessary
local function performPrint()
    operatingPrint = true
    while operatingPrint do
        local id,msg = rednet.receive()
        print("Command : "..msg)

        if id == activeCommander and string.find(msg, "$PC") == 1 then
            local cmds = split(msg, " ")

            --It's a bit of a hack, but those are the 2 methods required for a refuel
            if turtle.getFuelLevel() == 0 and cmds[2] ~= "SS" and cmds[2] ~= "RF" then
                rednet.send(id, "$3DPRINT OOF")
            elseif (tonumber(cmds[3])) and turtle.getItemCount(tonumber(cmds[3])) == 0 and
                    turtle.getFuelLevel() ~= 0 then
                rednet.send(id, "$3DPRINT DEP")
            else
                if cmds[2] == "RF" then cmds[3] = "64" end
                if type(commandList[cmds[2]]) == "function" then
                    commandList[cmds[2]](tonumber(cmds[3]))
                elseif type(commandList[cmds[2]]) == "table" then
                    for i=1,#commandList[cmds[2]] do
                        commandList[cmds[2]][i](tonumber(cmds[3]))
                    end
                end

                rednet.send(activeCommander, "$3DPRINT ACK")
            end
        end
    end
end

rednet.open("right")
term.clear()
term.setCursorPos(1,1)
if not os.getComputerLabel() then
    term.write("Name this computer:")
    os.setComputerLabel(io.read())
end
print("3D printer online")

while true do
    --Wait for activation
    respondToQuery()
    --Perform the print
    performPrint()
end